Carcinogenesis, Mutagenesis, Impairment of Fertility: Animal studies to assess the long-term carcinogenic and mutagenic potential or the effect on fertility in animals or humans of GUAIFENESIN-DM NR Liquid have not been performed.
Teratogenic Effects-Pregnancy Category C: Animal reproduction studies have not been conducted. Safe use in pregnancy has not been established relative to possible adverse effects on fetal development. Therefore, this product should not be used in pregnant patients, unless in the judgment of the physician, the potential benefits outweigh possible hazards.
Nursing Mothers: It is not known whether guaifenesin or dextromethorphan is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when these products are administered to a nursing woman and a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.
Laboratory Test Interactions: Guaifenesin or its metabolites may cause color interference with the VMA (vanilylmandelic acid) test for catechols. It may also falsely elevate the level of urinary 5-HIAA (5-hydroxyindoleacetic acid) in certain serotonin metabolite chemical tests because of color interference.
Drug Interactions: Serious toxicity may result if dextromethorphan is coadministered with monoamine oxidase inhibitors (MAOIs). The use of dextromethorphan hydrobromide may result in additive CNS depressant effects when coadministered with alcohol, antihistamines, psychotropics or other drugs, which produce CNS depression.
Information for Patients: Patients should be warned not to use this product if they are now taking a prescription monoamine oxidase inhibitor (MAOI) (certain drugs for depression, psychiatric or emotional conditions, or Parkinson's disease), or for 2 weeks after stopping the MAOI drug. If patients are uncertain whether a prescription drug contains an MAOI, they should be instructed to consult a health professional before taking such a product.